Assessment of Queen Conch, Lobatus gigas, Density, Middens and Permitting Requirements, in South Eleuthera, Bahamas by Erin Cash A thesis submitted to the Graduate Faculty of Auburn University in partial fulfillment of the requirements for the Degree of Master of Science Auburn, Alabama May 4th, 2013 Keywords: Lobatus gigas, Bahamas, conch, midden Approved by Dr. William C. Walton, Chair, Assistant Professor of Fisheries and Allied Aquacultures Dr. Anne Boettcher, University Director of Undergraduate Research Dr. Andy Danylchuk, Assistant Professor of Fish Conservation Dr. David LaDon Swann, Associate Professor of Fisheries and Allied Aquacultures Abstract Subject to subsistence and commercial harvest for decades, the queen conch, Lobatus gigas, has been subject to additional pressure in the Bahamas as stocks have been depleted in other countries that were historically prominent exporters. With concerns about local stocks and interest in culture of this species in the Bahamas an analysis of conch populations in south Eleuthera was executed. A survey of middens in the region to assess recent and historical fishing efforts was also performed. An area surveyed in 2003 (Clark et al., 2005) and determined to be a conch nursery ground was surveyed again in 2011 bi-monthly from July through November 2011 to assess population dynamics at nine sites in southern Eleuthera and assess any changes over time. Results suggest a decrease in density over time with no significant difference in total length over the two time periods. Middens in the area were also evaluated to quantify any change in size at harvest over time. Newer or “fresh” shells were significantly smaller than their “intermediate” and “old” counterparts. The information gathered proposes that juvenile harvest has increased substantially throughout the years, raising concerns about the sustainability of this important fishery. The permitting requirements for aquaculture of queen conch to alleviate this pressure are also discussed. ii Acknowledgements I would like to thank my committee members, Dr. Anne Boettcher, Dr. Andy Danylchuk, Dr. D. LaDon Swann and my advisor Dr. Bill Walton, for their advice, guidance and patience throughout this project. I would also like to thank the students, teachers, interns and staff of Cape Eleuthera Institute for allowing me to use their facilities and personnel throughout data collection. Without them this would never have been possible. Specifically I would like to thank Aaron Shultz, Sascha Danylchuk, Annabelle Brooks, Edd Brooks, Julie Claussen, David Philipp, Margaretmary Gilroy, Tarran Simms, Michael Piersak, Jason Selwyn, Bailey Clear, Jimmy Kilfoil and Justin Millar for helping me when no one else could. Thanks to my family for their support in this and every endeavor. iii Table of Contents Abstract ........................................................................................................................................... ii Acknowledgements ........................................................................................................................ iii List of Figures ................................................................................................................................ vi Chapter 1: Introduction and Literature Review .............................................................................. 1 1.2 Biology .................................................................................................................................. 6 1.3 Restoration ............................................................................................................................ 9 1.4 Aquaculture ......................................................................................................................... 10 1.5 Rationale ............................................................................................................................. 11 Chapter 2: Queen Conch Density and Midden Survey ................................................................. 12 2.1 Abstract ............................................................................................................................... 12 2.2 Introduction ......................................................................................................................... 12 2.3 Methods............................................................................................................................... 15 Density survey ...................................................................................................................... 15 Data Analyses ....................................................................................................................... 17 Midden Survey ...................................................................................................................... 17 Data Analyses ....................................................................................................................... 18 2.4 Results ................................................................................................................................. 23 Conch Abundance and Size Survey ...................................................................................... 23 Bimonthly Survey ................................................................................................................. 23 Comparison between years ................................................................................................... 24 Midden Survey ...................................................................................................................... 33 2.5. Discussion .......................................................................................................................... 50 Conch Abundance and Size Survey ...................................................................................... 50 Midden Survey ...................................................................................................................... 52 Implications........................................................................................................................... 54 iv Chapter 3: Permitting Requirements ............................................................................................. 56 4.1 Abstract ............................................................................................................................... 56 4.2 Introduction ......................................................................................................................... 56 4.3 Business Plan ...................................................................................................................... 57 4.3.1 Bahamas Investment Authority (BIA) ............................................................................. 57 4.3.2 Environmental Impact Assessment (EIA) ....................................................................... 58 4.4 Permit Submission .............................................................................................................. 58 4.5 Local Town Council ........................................................................................................... 59 4.6 Conclusion .......................................................................................................................... 59 References ..................................................................................................................................... 61 Appendices .................................................................................................................................... 68 Cape Eleuthera Institute ........................................................................................................ 68 v List of Figures Figure 1.1 Queen Conch Landings Western Atlantic………………….………………….……….3 Figure 1.2 Export of Queen Conch Western Atlantic…………………………....………......…….4 Figure 1.3 Queen Conch Landings Bahamas………………………….……….……….……….…5 Figure 1.4 Photograph Adult and Juvenile Queen Conch……………………..……….……......…5 Figure 2.1 Map of Nine Sites in Cape Eleuthera…………………………………....….….….….19 Figure 2.2 Photograph of Transect on Sea Floor…………………………………...….......….….20 Figure 2.3 Photograph of Total Length Measured with Vernier Calipers…………...….….....….20 Figure 2.4 Photograph of a Conch Midden……………………………………………......….….21 Figure 2.5 Map of 12 Conch Middens………………………………………………….....…......21 Figure 2.6 Photograph of Quadrat on Midden………………………………………........….…. 22 Figure 2.7 Photograph of Shell Conditions……………………………………………...……….22 Figure 2.8 Photograph of Lip Thickness Measurement………………………………......…..… 23 Figure 2.9 Average Total Conch Bimonthly Sample………………………………...…….....… 26 Figure 2.10 Average Total Length Bimonthly …………………………………………….....… 27 Figure 2.11 Average Lip Thickness Bimonthly ……………………………….……….…......... 28 Figure 2.12 Conch per m2 2003 and 2011 Comparison…………………………….……...….... 29 Figure 2.13 Average Total Length per Site 2003 and 2011 Comparison………….…………… 30 Figure 2.14 Average Total Length 2003 and 2011 Comparison………………………………...31 Figure 2.15 Average Total Length for Four Sites 2003 and 2011 Comparison…………………32 Figure 2.16 Frequency Histogram of Total Length for 2003 and 2011........................................33 vi Figure 2.17 Average Total Length Four Middens…………………………………….....……….36 Figure 2.18 Frequency Histogram for Total Length of IS Midden…………………………....…37